Because channel characteristics change over time in a wireless communication system, a transmitter knows channel information of a receiver and applies the channel information of the receiver depending on a situation, thereby improving performance of a communication system.
In particular, in a Multi-User (MU)—Multiple Input Multiple Output (MIMO) communication system or a cellular communication system in which the performance of the communication system is considerably affected by interference, a transmitter uses interference information of respective terminals, thereby considerably improving the performance of the system.
Generally, the transmitter may need to receive feedback information of a down link from a terminal in order to know the channel information of the down link.
Because the performance of the communication system is also considerably affected by interference from respective terminals in a virtual cellular network communication system, the transmitter needs to reduce performance degradation caused by the interference by using channel information of the respective terminals.
In contrast to an existing communication system according, according to the related art, because several distributed small base stations serve a plurality of terminals through sharing in the virtual cellular network communication system, a base station from which a terminal receives a service is not determined and an interference source varies in real time depending on the distributed small base station from which a service is provided. In addition, because each of the distributed small base stations uses imperfect channel information received from terminals when selecting terminals to be served by the distributed small base stations, there is a need for a feedback method considering such characteristics of a communication system.
However, an existing technology for improving the performance of a communication system relates to a system in which a base station that provides a service and an interference source are fixed for respective terminals. Therefore, the existing technology is not suitable to be applied to a virtual cellular network communication system in which respective base stations are not fixed with respect to whether to transmit signals or act as an interference source.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.